The availability of accurate positional information is often crucial for conducting military operations and other covert operations. The availability of GPS signals enable the use of smart bombs, and advanced navigation systems. The challenges of conducting operations in a GPS-denied or GPS-spoofed territory persist, and pose a serious threat to the success of future missions—threats that can result in consequential loss to life and property. In the case of GPS-spoofing, it has already been utilized to command an air vehicle to “safe-land” in hostile territory as a result of reliance on erroneous GPS data. In 2011, the nation of Iran captured a batwing stealth drone by spoofing the GPS signals that it received, tricking the drone into landing at what it believed was its home base, but was actually a location well within Iran's borders.
Early in 2016 the U.S. Air Force and the Navy each requested proposals for back-up technology that would supplement or supplant the use of GPS in the instance where a similar spoofing, or an outright denial of GPS signals may be experienced.
The present invention is directed to such a system that overcomes problems that may be experienced with position, navigation, and timing systems.
Some early position, navigation, and/or position/navigation-related technology is shown by the following U.S. Patent and Patent Application Publications: U.S. Pat. No. 2,470,787 to Nosker; U.S. Pat. No. 3,384,891 to Andersen; U.S. Pat. No. 3,430,234 to Wright; U.S. Pat. No. 3,471,856 to Laughlin; 3,495,260 to Laughlin; U.S. Pat. No. 3,554,995 to Bottenberg; U.S. Pat. No. 3,611,379 to Deckett; U.S. Pat. No. 3,705,404 to Chisholm; U.S. Pat. No. 3,742,498 to Dunn; U.S. Pat. No. 3,789,409 to Easton; U.S. Pat. No. 3,810,179 to Merrick; U.S. Pat. No. 3,876,970 to Reitzig; U.S. Pat. No. 3,852,750 to Klein; U.S. Pat. No. 3,880,553 to Bates; U.S. Pat. No. 3,988,734 to Elwood; U.S. Pat. No. 4,114,155 to Raab; U.S. Pat. No. 4,161,730 to Anderson; U.S. Pat. No. 4,179,693 to Evans; U.S. Pat. No. 4,253,098 to Blythe; U.S. Pat. No. 4,359,733 to O'Neill; U.S. Pat. No. 4,386,355 to Drew; U.S. Pat. No. 4,472,720 to Reesor; U.S. Pat. No. 4,839,656 to O'Neill; U.S. Pat. No. 4,987,420 to Inamiya; U.S. Pat. No. 5,014,066 to Counselman; U.S. Pat. No. 5,017,926 to Ames; U.S. Pat. No. 5,432,520 to Schneider; U.S. Pat. No. 5,521,817 to Burdoin; U.S. Pat. No. 5,944,770 to Enge; U.S. Pat. No. 5,999,124 to Sheynblat; U.S. Pat. No. 5,999,129 to Rose; U.S. Pat. No. 6,167,263 to Campbell; U.S. Pat. No. 6,249,252 to Dupray; U.S. Pat. No. 6,407,703 to Minter; U.S. Pat. No. 6,529,820 to Tomescu; U.S. Pat. No. 6,618,016 to Hannan; U.S. Pat. No. 6,785,553 to Chang; U.S. Pat. No. 6,819,291 to Lackey; U.S. Pat. No. 6,911,936 to Stayton; U.S. Pat. No. 6,961,019 to McConnell; U.S. Pat. No. 7,043,355 to Lai; 2007/0001898 to Twitchell; 2007/0222665 to Koeneman; U.S. Pat. No. 7,292,935 to Yoon; 2008/0042901 to Smith; 2008/0158059 to Bull; U.S. Pat. No. 7,460,870 to Moeglein; U.S. Pat. No. 7,711,476 to Chiou; U.S. Pat. No. 7,904,244 to Sugla; U.S. Pat. No. 7,990,314 to Liao; U.S. Pat. No. 8,086,351 to Gaudiano; U.S. Pat. No. 8,155,666 to Alizadeh-Shadbiz U.S. Pat. No. 8,922,421 to Pomietlasz; and U.S. Pat. No. 9,218,741 to Wu.